t.p.a.C.__metaclass__(type) : class documentation

This metaclass keeps track of all of the Command.responder-decorated
methods defined since the last CommandLocator subclass was defined. It
assumes (usually correctly, but unfortunately not necessarily so) that
those commands responders were all declared as methods of the class being
defined. Note that this list can be incorrect if users use the
Command.responder decorator outside the context of a CommandLocator class
declaration.

Command responders defined on subclasses are given precedence over those
inherited from a base class.

The Command.responder decorator explicitly cooperates with this
metaclass.